Communication and Perception
One way of communication that has been studied in gray brocket deer is scent-marking, which would include urination, defecation, forehead rubbing and thrashing. There is a difference in frequency of scent-marking between females, as well as between males and juveniles. It was also observed that females and juveniles marked more often in the core of their home range versus the males who often marked outside their home range. (Black-Dècima, 2000)
As is true for virtually all mammals, there are probably some other forms of communication as well. These deer probably use some vocalizations. Visual signals and postures may be important, and physcial contact signals are probably important between mother and infant, as well as between mates.